Just buy a separate machine to apply paste. You'll be able to run faster, (by doing more at the same time) and you can probably find an air-over-syringe system for less than $2000USD. At the end of the day, that's probably less than you'll spend in time and parts trying to build a 4C to do what you'd like. A cheap solution I might recommend is getting a dated Nordson-Asymtek machine like the Century/Automove series. We've been using at least one of their machines from the same era for the past 5 years for prototyping assemblies. Works fine for our purposes, but I'm not sure what mix of parts you're using.

Hi, Yes you can add a paste dispenser to the Quad 4C. The system will dispense DOTS and DOT patterns, no lines. We sell kits to add the dispenser. It takes about 4hours to install the kit. We also sell Camalot dispensers, benchtop & floor models.